The strain h(t) produced by a smirch in LISA is given by h(t) = −-A(t)cos[(t) + φ(t)]

2005, John M. T. Thompson, Advances in Astronomy: From the Big Bang to the Solar System, page 133, ISBN 1860945775.

By observing a smirch, LISA offers a unique opportunity to directly map the spacetime geometry around the central object and test whether or not this structure is in accordance with the expectations of general realtivity.